Floor material using pla resin

ABSTRACT

Disclosed is a flooring material using an environment-friendly PLA resin. According to the present invention, the flooring material using the PLA resin comprises: a base layer; a print layer which is formed on top of the base layer, and has a print pattern on an upper side thereof; and a transparent layer which is formed on top of the print layer, wherein one or more of the base layer, the print layer, and the transparent layer include polylactic acid (PLA) resin.

TECHNICAL FIELD

The present invention relates to flooring materials, and moreparticularly, to a flooring material, which includes a base layer, abalance layer and the like, formed using a polylactic acid (PLA) resin,an environmentally friendly plasticizer such as acetyl tributyl citrate(ATBC) to realize environmental friendliness, and an acrylic copolymeras a melt strength enhancer, thereby facilitating calendering, pressing,and the like.

BACKGROUND ART

Flooring materials used for buildings, such as houses, apartments,offices, and stores, generally include petroleum resins such aspolyvinyl chloride (PVC).

Such flooring materials are manufactured by extrusion or calendering ofPVC resins. However, since PVC resins are derived from petroleum, adifficulty may occur in terms of supply of raw materials in the futuredue to the exhaustion of petroleum resources.

Further, PVC flooring materials generally generate a large amount oftoxic substances in use or when discarded in view of environmentalconsiderations.

DISCLOSURE Technical Problem

The present invention is directed to providing a flooring material whichemploys a PLA resin, thereby solving a problem regarding supply of rawmaterials for respective layers of the flooring material while realizingenvironmental friendliness.

Technical Solution

One aspect of the present invention provides a flooring material using apolylactic acid (PLA) resin, which includes a base layer; a print layerformed on top of the base layer and having a printed pattern on an uppersurface of the print layer; and a transparent layer formed on top of theprint layer, wherein at least one of the base layer, the print layer andthe transparent layer includes a PLA resin.

Another aspect of the present invention provides a flooring materialusing a polylactic acid (PLA) resin, which includes a base layer; aprint layer formed on top of the base layer and having a printed patternon an upper surface of the print layer; a transparent layer formed ontop of the print layer; and a release layer formed on a lower surface ofthe base layer, wherein at least one of the base layer, the print layer,the transparent layer and the release layer includes a PLA resin.

The flooring material may further include a surface treatment layerformed on top of the transparent layer.

Advantageous Effects

According to the present invention, a PLA resin based on plant resourcesis employed instead of PVC derived from petroleum resources, therebysolving a problem regarding supply of raw materials.

In addition, the flooring material according to the present inventiongenerates few toxic substances such as CO₂ in fabrication of layers suchas a base layer, a release layer, and the like, and facilitates disposalof the flooring material, thereby realizing environmental friendliness.

Further, in the flooring material according the present invention, thebase layer and the release layer are formed using wood flour and pineresin, thereby providing the texture of natural wood and the uniquefragrance of trees.

Further, according to the present invention, the PLA resin includes anacrylic copolymer as a melt strength enhancer, thereby facilitating meltextrusion, calendering or pressing of the PLA resin.

DESCRIPTION OF DRAWINGS

FIGS. 1 to 4 are side-sectional views of a flooring material using a PLAresin according to exemplary embodiments of the present invention.

MODE FOR INVENTION

The above and other aspects, features, and advantages of the inventionwill become apparent from the detailed description of the followingembodiments in conjunction with the accompanying drawings. It should beunderstood that the present invention is not limited to the followingembodiments and may be embodied in different ways, and that theembodiments are given to provide complete disclosure of the inventionand to provide a thorough understanding of the invention to thoseskilled in the art. The scope of the invention is defined only by theclaims. Like components will be denoted by like reference numeralsthroughout the specification.

Exemplary embodiments of the present invention will be described indetail with reference to the accompanying drawings.

FIG. 1 is a side-sectional view of a flooring material using a PLA resinaccording to one exemplary embodiment of the present invention.

In FIG. 1, the flooring material includes a base layer 110, a printlayer 120, and a transparent layer 130. In the flooring materialaccording to this embodiment, at least one of the base layer 110, theprint layer 120 and the transparent layer 130 includes a polylactic acid(PLA) resin.

FIG. 2 is a side-sectional view of a flooring material using a PLA resinaccording to another exemplary embodiment of the present invention.

In FIG. 2, the flooring material includes a base layer 110, a printlayer 120, a transparent layer 130, and a release layer 140 formed on alower side of the base layer 110. In the flooring material according tothis embodiment, at least one of the base layer 110, the print layer120, the transparent layer 130 and the release layer 140 includes a PLAresin.

The PLA resin is a thermoplastic polyester of lactide or lactic acid,which can be prepared by polymerization of lactic acid obtained byfermentation of starch extracted from renewable plant resources, such ascorn and potato. Since corn and potato are renewable plant resources,the PLA resin based on such plant resources may effectively solveproblems caused by depletion of petroleum resource.

Further, the PLA resin is an environmentally friendly material in thatit discharges remarkably less toxic substances to the environment, forexample, CO₂, in use or when discarded than petroleum-based materials,for example, polyvinyl chloride (PVC), and is readily biodegraded whendiscarded.

The PLA resin may be generally classified into a crystalline PLA (c-PLA)resin and an amorphous PLA (a-PLA) resin. Since the crystalline PLAresin can cause bleeding of a plasticizer towards a sheet surface, theamorphous PLA resin may be used. The amorphous PLA resin provides anadvantage of eliminating use of compatibilizing agents, which are addedto prevent bleeding of the plasticizer. When using the amorphous PLAresin, a 100% amorphous PLA resin may be used as the PLA resin. Asneeded, a PLA resin exhibiting both crystalline and amorphous propertiesmay be used.

When one of the base layer 110, the print layer 120, the transparentlayer 130, and the release layer 140 includes the PLA resin, the PLAresin may include a non-phthalate plasticizer or an acrylic copolymer asa melt strength enhancer.

The non-phthalate plasticizer is an environmentally friendly plasticizerand softens the PLA resin to improve thermoplasticity, facilitatingmolding at high temperature. In one embodiment, acetyl tributyl citrate(ATBC) may be used as the non-phthalate plasticizer.

For the base layer 110, the non-phthalate plasticizer may be present inan amount of 5 to 100 parts by weight based on 100 parts by weight ofthe PLA resin, and for the print layer 120 or the release layer 140, thenon-phthalate plasticizer may be present in an amount of 5 to 60 partsby weight based on 100 parts by weight of the PLA resin. For thetransparent layer 130, the non-phthalate plasticizer may be present inan amount of 5 to 50 parts by weight based on 100 parts by weight of thePLA resin.

If the amount of the non-phthalate plasticizer is less than 5 parts byweight based on 100 parts by weight of the PLA resin in the respectivelayer, hardness of the PLA resin can increase, thereby reducingprocessability. If the non-phthalate plasticizer is added in an amountexceeding the above ranges in the respective layers, compatibility withother components decreases, thereby deteriorating physical properties.

An acrylic copolymer is used as the melt strength enhancer. Since thePLA resin has low melt strength or thermal resistance, the acryliccopolymer serves to improve melt strength of the PLA resin and permitcalendering and pressing by complementing such drawbacks of the PLAresin.

In each of the base layer 110, the print layer 120, the transparentlayer 130, and the release layer 140, the acrylic copolymer may becommonly present in an amount of 0.1 to 20 parts by weight based on 100parts by weight of the PLA resin. If the amount of the acrylic copolymeris less than 0.1 parts by weight, the melt efficiency and melt strengthof the PLA resin cannot sufficiently improve. If the amount of theacrylic copolymer exceeds 20 parts by weight, manufacturing costs of therespective layers of the flooring material can be increased and overallphysical properties of the respective layers can be deteriorated due toinappropriate compatibility with other components forming the respectivelayers.

Further, when any one of the base layer 110, the print layer 120, thetransparent layer 130, and the release layer 140 includes the PLA resin,the PLA resin may further include at least one of a lubricant, a chainextender, and an anti-hydrolysis agent.

The lubricant may be added to the PLA resin to prevent the resin fromadhering to a calendar roll or press roll during processes such ascalendaring, pressing and the like.

Although there are various kinds of lubricants, environmentally friendlylubricants, such as higher fatty acids, may be adopted in someembodiments of the invention, specifically, a saturated fatty acid withan 18 carbon chain, such as stearic acid, may be used.

In each of the base layer 110, the print layer 120, the transparentlayer 130, and the release layer 140, the lubricant may be commonlypresent in an amount of 0.01 to 10 parts by weight based on 100 parts byweight of the PLA resin. If the amount of the lubricant is less than0.01 parts by weight based on 100 parts by weight of the PLA resin, thelubricant does not work effectively. If the amount of the lubricantexceeds 10 parts by weight based on 100 parts by weight of the PLAresin, the PLA resin can be deteriorated in terms of impact resistance,heat resistance, and gloss.

The chain extender serves to improve tensile strength, heat resistanceand the like by increasing molecular weight through chain extension.

Examples of the chain extender may include diisocyanate, epoxy groupcopolymers, and hydroxycarboxylic compounds, without being limitedthereto.

In each of the base layer 110, the print layer 120, the transparentlayer 130, and the release layer 140, the chain extender may be commonlypresent in an amount of 0.01 to 10 parts by weight based on 100 parts byweight of the PLA resin. If the amount of the chain extender is lessthan 0.01 parts by weight based on 100 parts by weight of the PLA resin,the chain extender does not work effectively, and if the amount of thechain extender exceeds 10 parts by weight based on 100 parts by weightof the PLA resin, gloss of the PLA resin can be deteriorated.

The anti-hydrolysis agent serves to prevent deterioration in mechanicalproperties of the PLA resin including impact resistance throughhydrolysis of the PLA resin.

Any typical anti-hydrolysis agent including polycarbodiimide,carbodiimide, oxazoline and the like may used

In each of the base layer 110, the print layer 120, the transparentlayer 130, and the release layer 140, the anti-hydrolysis agent may becommonly present in an amount of 10 parts by weight or less based on 100parts by weight of the PLA resin. If the amount of the anti-hydrolysisagent exceeds 10 parts by weight based on 100 parts by weight of the PLAresin, molding processibility can be deteriorated and manufacturingcosts can significantly increase since the anti-hydrolysis agent isexpensive.

Meanwhile, when the PLA resin is applied to the print layer 120, each ofthe layers may further include calcium carbide (CaCO₃) as reinforcinginorganic fillers, or titanium dioxide (TiO₂) as white pigments foraesthetic purposes.

In the base layer 110, calcium carbide may be present in an amount of1,000 parts by weight or less based on 100 parts by weight of the PLAresin; in the print layer 120, calcium carbide may be present in anamount of 100 parts by weight or less based on 100 parts by weight ofthe PLA resin; and in the release layer 140, calcium carbide may bepresent in an amount of 500 parts by weight or less based on 100 partsby weight of the PLA resin. Further, titanium dioxide may be present inan amount of 50 parts by weight or less in the print layer 120, based on100 parts by weight of the PLA resin. If the amount of calcium carbideor titanium dioxide exceeds these ranges, there is a problem ofdeterioration in processibility due to reduction in coupling forcebetween components.

The base layer 110 or the release layer 140 may further include woodflour or pine resin to provide the texture of natural wood and theunique fragrance of trees.

In each of the base layer 110 and the release layer 140, wood flour maybe commonly present in an amount of 200 parts by weight or less based on100 parts by weight of the PLA resin, and pine resin may be commonlypresent in an amount of 20 parts by weight or less based on 100 parts byweight of the PLA resin. Although the effect of providing the texture ofnatural wood can increase with increasing amounts of the wood flour andpine resin in the base layer 110 and the release layer 140, the amountsof the wood flour and pine resin exceeding these ranges can causedeterioration in formability without increasing the effect of providingthe texture of natural wood.

Next, each of the base layer 110, the print layer 120, the transparentlayer 130 and the release layer 140 will be described with reference toFIG. 1 and FIG. 2.

In the present invention, the base layer 110 is a fundamental layer ofthe flooring material and serves to support the print layer 120 and thetransparent layer 130 while absorbing impact applied thereto.

The base layer 110 may have a thickness of 1.0 to 5.0 mm. If thethickness of the base layer 110 is less than 1.0 mm, such functions ofthe base layer cannot be sufficiently realized, and if the thickness ofthe base layer 110 exceeds 5.0 mm, the amount of the PLA resinincreases, causing an increase in manufacturing costs of the flooringmaterial.

As described above, the base layer 110 may be formed using a PLA resin,which contains a non-phthalate plasticizer, an acrylic copolymer, andthe like. In this case, the PLA resin for the base layer may furtherinclude a lubricant, a chain extender, an anti-hydrolysis agent, calciumcarbide, wood flour, pine resin, and the like, which may be used aloneor in combination of two or more thereof.

The print layer 120 is formed on top of the base layer 110 and alsoincludes a PLA resin. The print layer may have a pattern, which isformed on an upper surface thereof in a variety of ways, includingtransfer printing, gravure printing, screen printing, offset printing,rotary printing, flexo-printing, and ink-jet printing, to provide anaesthetic appearance to the flooring material.

The print layer 120 may be formed using a PLA resin, which contains anon-phthalate plasticizer, an acrylic copolymer, and the like. In thiscase, the PLA resin may further include a lubricant, a chain extender,an anti-hydrolysis agent, calcium carbide, titanium dioxide, and thelike, which may be used alone or in combination of two or more thereof.

The print layer 120 may have a thickness ranging from 0.01 to 0.3 mm. Ifthe thickness of the print layer 120 is less than 0.01 mm, it isdifficult to print the pattern thereon, and if the thickness of theprint layer 120 exceeds 0.3 mm, manufacturing costs of the flooringmaterial can be increased.

The transparent layer 130 is formed on top of the print layer 120 toprovide a volumetric appearance to the flooring material whileprotecting the pattern formed on the print layer 120.

In this invention, the transparent layer 130 is formed using a PLAresin, which contains a non-phthalate plasticizer and an acryliccopolymer, and may further include a lubricant, a chain extender, ananti-hydrolysis agent, and the like, as described above.

The transparent layer 130 may have a thickness of 0.10 to 1.0 mm. If thethickness of the transparent layer is less than 0.10 mm, it is difficultto protect the pattern formed on the print layer and the volumetricappearance of the flooring material is deteriorated. If the thickness ofthe transparent layer exceeds 1.0 mm, the manufacturing costs of theflooring material can be increased without significant improvement ofthe effects provided by the transparent layer.

In this invention, the release layer 140 will be brought into contactwith a floor in construction of the flooring material on the floor andprotects the backside of the flooring material while absorbing impactapplied thereto.

The release layer 140 may be formed using a PLA resin, which contains anon-phthalate plasticizer, an acrylic copolymer, a lubricant, a chainextender, an anti-hydrolysis agent, and the like. In the release layer,the PLA resin may further include at least one of calcium carbide, woodflour, and pine resin. The release layer 140 may have a thickness of0.10 to 2.0 mm to provide structural stability to the flooring material.If the thickness of the release layer 140 is less than 0.10 mm, therelease layer does not sufficiently function, such that the effect ofprotecting the backside of the flooring material or absorbing impact isnot sufficiently exhibited. If the thickness of the release layer 140exceeds 2.0 mm, manufacturing costs of the flooring material can beincreased.

FIG. 3 and FIG. 4 are side sectional views of flooring materials using aPLA resin according to other exemplary embodiments of the presentinvention, each of which includes a surface treatment layer 150 on thesurface of the flooring material shown in FIGS. 1 and 2.

In these embodiments, the surface treatment layer 150 is formed on thetransparent layer 130 to improve surface qualities of the flooringmaterial, including scratch resistance and abrasion resistance whileenhancing contamination resistance in order to facilitate cleaning. Thesurface treatment layer 150 may include polyurethane, urethane acrylate,or wax.

The surface treatment layer 130 may be formed in various ways. Forexample, when urethane acrylate is used, a urethane acrylate UV-curablecomposition may be applied to an upper side of a wood chip through layer120 and cured through UV curing, thereby forming the surface treatmentlayer. Alternatively, a thermosetting wax may be applied to the upperside of the wood chip through layer 120, followed by drying in a hot airoven, thereby forming the surface treatment layer.

The surface treatment layer 150 may have a thickness ranging from 0.01to 0.1 mm. If the thickness of the surface treatment layer 150 is lessthan 0.01 mm, it is difficult to improve physical properties includingscratch resistance, and if the thickness of the surface treatment layer150 exceeds 0.1 mm, surface treatment entails excessive cost and theflooring material can be deteriorated in terms of appearance.

According to the present invention, there is no particular restrictionas to a method of manufacturing the base layer and other layersincluding a PLA resin through calendering or the like. For example, themethod may include mixing and kneading the aforementioned componentsincluding the PLA resin, and calendering the kneaded mixture to form adesired sheet shape.

Here, mixing and kneading the components may be carried out, forexample, on liquid or powdery raw materials using a super mixer,extruder, kneader, or 2 or 3-roll. Mixing and kneading may be repeatedlyperformed in multiple stages so as to efficiently mix the componentssuch that the mixed components are kneaded at about 120 to 200° C. usinga Banbury mixer, and the kneaded components are subjected to primary andsecondary mixing at about 120 to 200° C. using a 2-roll.

Also, there is no particular restriction as to a method of manufacturinga sheet-shaped base layer, which involves subjecting the mixedcomponents to calendaring. For example, the base layer may be formedusing a general device, e.g., an inverted “L” four-roll calender.

Further, calendering conditions may be suitably adjusted inconsideration of compositions of used resin compositions. For example,calendering may be carried out at a temperature ranging from about 120to about 200° C.

Preparation of Flooring Material According to Example and ComparativeExample

Next, the present invention will be described in detail with referenceto some examples of the flooring material according to the presentinvention. These examples are provided for illustration only and are notto be in any way construed as limiting the present invention.

A description of details apparent to those skilled in the art will beomitted herein.

Preparation of Transparent Layer

(1) Preparation of Transparent Layer Via Calendering

A PLA resin, a chain extender, an anti-hydrolysis agent, a plasticizer,a melt strength enhancer and a lubricant were placed in a Banbury mixerand kneaded at 140° C., followed by primary and secondary mixing with a2-roll at 140° C. Then, the prepared mixture was subjected tocalendaring at 130° C. to form a sheet having a thickness of about 0.5mm.

(2) Preparation of Transparent Layer Via Extrusion

An about 0.5 mm thick transparent layer was prepared by mixing a PLAresin, a chain extender, an anti-hydrolysis agent and a plasticizer,followed by extrusion.

Preparation of Print Layer

A PLA resin, a plasticizer, a melt strength enhancer, a lubricant, achain extender, an anti-hydrolysis agent, calcium carbide, and titaniumdioxide were mixed, followed by the same calendering process as inpreparation of the transparent layer, thereby providing a white sheethaving a thickness of about 0.2 mm.

Preparation of Base Layer

A PLA resin, a plasticizer, a melt strength enhancer, a lubricant, achain extender, an anti-hydrolysis agent, calcium carbide, wood flour,and pine resin were mixed, followed by the same calendering process asin preparation of the transparent layer, thereby providing a white sheethaving a thickness of about 2 mm.

Preparation of Release Layer

A PLA resin, a plasticizer, a melt strength enhancer, a lubricant, achain extender, an anti-hydrolysis agent, calcium carbide, wood flour,and pine resin were mixed, followed by the same calendering process asin preparation of the transparent layer, thereby providing a sheethaving a thickness of about 0.7 mm.

Formation of Surface Treatment Layer

A print layer and a release layer were formed on upper and lower sidesof the prepared base layer through thermal stacking to form a sheetprint layer, which in turn was subjected to transfer printing to form atransparent layer on the top thereof. Then, the transparent layer wassubjected to embossing treatment using an embossing roll, followed byapplication of a urethane acrylic UV-curable paint to the surface of theembossed transparent layer, and UV radiation to form an about 0.05 mmthick surface treatment layer, thereby providing a flooring material. Inthese examples, the transparent layer, the print layer, the base layerand the release layer were formed using a PLA resin.

For the flooring materials according to the examples and the comparativeexamples, all of the transparent layer, the print layer, the base layer,and the release layer were prepared, or some layers were prepared forevaluation of physical properties. Here, the compositions of thetransparent layer, the print layer, the base layer, and the releaselayer are listed in Tables 1 and 2 (based on 100 parts by weight ofPLA), and the amounts of the plasticizers, melt strength enhancers,lubricants, chain extenders, and anti-hydrolysis agents used for theexamples and the comparative examples were listed in Table 3.

TABLE 1 Melt Anti- Kind of strength Chain hydrolysis Calcium TitaniumWood Pine Sample layer PLA Plasticizer enhancer Lubricant extender agentcarbide dioxide flour resin Example 1 Transparent 100 5 5 3 2 1 — — — —layer (Calendering) Print layer 100 10 5 3 2 1 100 10 Base layer 100 205 3 3 2 500 — 10 5 Release 100 15 5 3 2 1 250 — 10 5 layer Example 2Transparent 100 5 7 3 2 1 — — — — layer (Calendering) Example 3Transparent 100 5 5 5 2 1 — — — — layer (Calendering) Example 4Transparent 100 5 5 3 3 1 — — — — layer (Calendering) Example 5Transparent 100 5 5 3 2 2 — — — — layer (Calendering) Example 6 Printlayer 100 10 5 3 2 1 200 — — — Example 7 Print layer 100 10 5 3 2 1 100 8 — — Example 8 Print layer 100 10 5 3 2 1 100 15 — — Example 9 Printlayer 100 15 5 3 2 1 100 10 — — Example Base layer 100 20 5 3 2 2 500 —10 5 10 Example Base layer 100 20 5 3 3 1 500 — 10 5 11 Example Release100 15 5 3 2 1 300 — 10 5 12 layer Example Release 100 15 5 3 1 1 250 —10 5 13 layer Example Release 100 20 5 3 2 1 300 — 10 5 14 layer

TABLE 2 Melt Anti- Kind of strength Chain hydrolysis Calcium TitaniumWood Pine Sample layer PLA Plasticizer enhancer Lubricant extender agentcarbide dioxide flour resin Comparative Transparent 100 5 5 3 2 1 — — —— Example 1 layer (Calendering) Comparative Print layer 100 10 5 3 2 1100 20 — — Example 2 Comparative Release 100 15 5 3 2 1 250 20 10 5Example 3 layer Comparative Base layer 100 20 5 3 3 2 500 10 10 5Example 4 Comparative Transparent 100 5 — 3 2 1 — — — — Example 5 layer(Calendering) Comparative Print layer 100 10 — 3 2 1 100 20 — — Example6 Comparative Release 100 15 — 3 2 1 250 20 10 5 Example 7 layerComparative Base layer 100 20 — 3 3 2 500 10 10 5 Example 8 ComparativeTransparent 100 5 5 3 — 1 — — — — Example 9 layer (Calendering)Comparative Transparent 100 5 5 3 2 — — — — — Example layer 10(Calendering) Comparative Transparent 100 5 — — 2 1 — — — — Examplelayer 11 (Extrusion) Print layer 100 10 5 3 2 1 100 20 Base layer 100 205 3 3 2 500 10 10 5 Release 100 15 5 3 2 1 250 20 10 5 layer ComparativeTransparent 100 5 — 3 2 1 — — — — Example layer 12 (Calendering)Comparative Transparent 100 10 5 — 2 1 — — — — Example layer 13(Calendering) Comparative Release 100 15 5 3 2 — 250 20 10 5 Examplelayer 14 Comparative Transparent 100 5 3 3 2 1 — — — — Example layer 15(Calendering)

TABLE 3 Melt strength Anti-hydrolysis Sample Plasticizer enhancerLubricant Chain extender agent Examples 1~14 ATBC acrylic stearic acidstyrene- polycarbodiimide copolymer methacrylate- glycidyl acrylatepolymer Comparative DOP(dioctyl acrylic stearic acid styrene-polycarbodiimide Examples 1~4 Phthalate) copolymer methacrylate-glycidyl acrylate polymer Comparative ATBC No addition of stearic acidstyrene- polycarbodiimide Examples 5~8 melt strength methacrylate-enhancer glycidyl acrylate polymer Comparative ATBC acrylic stearic acidstyrene- polycarbodiimide Example 9 copolymer methacrylate- glycidylacrylate polymer Comparative ATBC acrylic stearic acid styrene- Noaddition of anti- Example 10 copolymer methacrylate- hydrolysis agentglycidyl acrylate polymer Comparative ATBC No addition of No addition ofstyrene- polycarbodiimide Example 11 melt strength lubricantmethacrylate- (Transparent enhancer glycidyl acrylate layer extrusion)polymer Comparative ATBC No addition of stearic acid styrene-polycarbodiimide Example 12 melt strength methacrylate- enhancerglycidyl acrylate polymer Comparative ATBC acrylic No addition ofstyrene- polycarbodiimide Example 13 copolymer lubricant methacrylate-glycidyl acrylate polymer Comparative ATBC acrylic stearic acid styrene-No addition of anti- Example 14 copolymer methacrylate- hydrolysis agentglycidyl acrylate polymer Comparative ATBC acrylic stearic acid styrene-polycarbodiimide Example 15 copolymer methacrylate- glycidyl acrylatepolymer

Physical properties of the flooring materials according to the examplesand the comparative materials were evaluated. Evaluation results areshown in Tables 4 and 5 (based on relative evaluation with a perfectscore being 5 points).

TABLE 4 Impact Thermal Molding Economic Calendering Tensile Sample Kindof layer resistance resistance Gloss processibility feasibilityavailability strength Example 1 Transparent 5 4 5 5 4 4 4 layer(Calendering) Print layer 4 4 5 4 4 4 4 Base layer 4 4 — 5 4 5 4 Releaselayer 4 4 4 5 4 5 5 Example 2 Transparent 5 5 5 5 4 3 5 layer(Calendering) Example 3 Transparent 5 5 4 5 5 4 3 layer (Calendering)Example 4 Transparent 5 5 4 5 3 5 5 layer (Calendering) Example 5Transparent 5 5 4 5 3 5 5 layer (Calendering) Example 6 Print layer 3 44 5 5 3 3 Example 7 Print layer 5 4 4 5 5 4 4 Example 8 Print layer 5 45 5 4 4 4 Example 9 Print layer 5 3 4 5 4 4 3 Example 10 Base layer 5 45 4 5 3 4 Example 11 Base layer 5 3 5 5 5 4 4 Example 12 Release layer 34 3 4 5 4 4 Example 13 Release layer 3 3 4 3 5 3 3 Example 14 Releaselayer 5 3 4 4 4 1 3

TABLE 5 Kind of Impact Thermal Molding Economic Calendering TensileSample layer resistance resistance Gloss processibility feasibilityavailability strength Comparative Transparent 4 3 4 2 5 2 3 Example 1layer (Calendering) Comparative Print layer 4 1 3 1 5 1 3 Example 2Comparative Release 4 2 3 2 5 2 3 Example 3 layer Comparative Base layer4 3 — 3 5 3 3 Example 4 Comparative Transparent 2 3 4 1 4 1 3 Example 5layer Comparative Print layer 2 2 4 1 4 1 3 Example 6 ComparativeRelease 3 3 4 1 4 1 3 Example 7 layer Comparative Base layer 1 3 — 1 4 13 Example 8 Comparative Transparent 3 3 5 2 5 1 2 Example 9 layer(Calendering) Comparative Transparent 3 3 5 3 5 2 3 Example 10 layer(Calendering) Comparative Transparent 4 5 5 5 4 — 5 Example 11 layer(Extrusion) Print layer 4 4 5 4 4 4 4 Base layer 4 4 — 5 4 5 4 Release 44 4 5 4 5 5 layer Comparative Transparent 2 3 4 1 4 1 3 Example 12 layer(Calendering) Comparative Transparent 5 2 4 3 4 1 4 Example 13 layer(Calendering) Comparative Release 4 3 5 3 5 2 3 Example 14 layerComparative Transparent 3 3 4 2 4 2 3 Example 15 layer (Calendering)

Although some exemplary embodiments of the present invention have beendescribed with reference to the accompanying drawing, it will beunderstood by those skilled in the art that these embodiments areprovided for illustrative purposes only, and various modifications,changes, alterations and equivalent embodiments can be made withoutdeparting from the scope of the present invention. Therefore, the scopeand spirit of the present invention should be defined by theaccompanying claims.

1. A flooring material using a polylactic acid (PLA) resin, comprising:a base layer; a print layer formed on top of the base layer and having aprinted pattern on an upper surface of the print layer; and atransparent layer formed on the top of the print layer, wherein at leastone of the base layer, the print layer and the transparent layerincludes a PLA resin.
 2. The flooring material of claim 1, comprisingbalance layer formed on a lower surface of the base layer, wherein thebalance layer includes a PLA resin.
 3. The flooring material of claim 1,further comprising: a surface treatment layer formed on top of thetransparent layer.
 4. The flooring material of claim 1, wherein the PLAresin comprises at least one of a non-phthalate plasticizer, an acryliccopolymer as a melt strength enhancer, a lubricant, a chain extender,and an anti-hydrolysis agent.
 5. The flooring material of claim 4,wherein the PLA resin further comprises at least one of calcium carbide,titanium dioxide, wood flour, and pine resin.
 6. The flooring materialof claim 4, wherein the transparent layer comprises 5 to 50 parts byweight of the non-phthalate plasticizer and 0.1 to 20 parts by weight ofthe acrylic copolymer based on 100 parts by weight of the PLA resin. 7.The flooring material of claim 6, wherein the transparent layer furthercomprises at least one of 0.01 to 10 parts by weight of the lubricant,0.01 to 10 parts by weight of the chain extender, and 10 parts by weightof the anti-hydrolysis agent based on 100 parts by weight of the PLAresin.
 8. The flooring material of claim 1, wherein the transparentlayer has a thickness of 0.10 to 1.0 mm.
 9. The flooring material ofclaim 4, wherein the print layer comprises 5 to 60 parts by weight ofthe non-phthalate plasticizer and 0.1 to 20 parts by weight of the meltstrength enhancer based on 100 parts by weight of the PLA resin.
 10. Theflooring material of claim 9, wherein the print layer further comprisesat least one of 0.01 to 10 parts by weight of the lubricant, 0.01 to 10parts by weight of the chain extender, 10 parts by weight or less of theanti-hydrolysis agent, 100 parts by weight or less of calcium carbide(CaCO₃), and 50 parts by weight or less of titanium dioxide (TiO₂) basedon 100 parts by weight of the PLA resin.
 11. The flooring material ofclaim 1, wherein the print layer has a thickness of 0.01 to 0.3 mm. 12.The flooring material of claim 4, wherein the base layer comprises 5 to100 parts by weight of the non-phthalate plasticizer and 0.1 to 20 partsby weight of the acrylic copolymer based on 100 parts by weight of thePLA resin.
 13. The flooring material of claim 12, wherein the base layerfurther comprises 0.01 to 10 parts by weight of a higher fatty acid asthe lubricant, 0.01˜10 parts by weight of the chain extender, 10 partsby weight or less of the anti-hydrolysis agent, calcium carbide 1,000parts by weight or less, 200 parts by weight or less of wood flour, and20 parts by weight or less of pine resin based on 100 parts by weight ofthe PLA resin.
 14. The flooring material of claim 1, wherein the baselayer has a thickness of 1.00 to 5.0 mm.
 15. The flooring material ofclaim 4, wherein the release layer comprises 5 to 60 parts by weight ofthe non-phthalate plasticizer and 0.1˜20 parts by weight of the acryliccopolymer based on 100 parts by weight of the PLA resin.
 16. Theflooring material of claim 15, wherein the release layer furthercomprises at least one of 0.01 to 10 parts by weight of the lubricant,0.01 to 10 parts by weight of the chain extender, 10 parts by weight orless of the anti-hydrolysis agent, 500 parts by weight or less ofcalcium carbide, 200 parts by weight or less of wood flour, and 20 partsby weight or less of pine resin based on 100 parts by weight of the PLAresin.
 17. The flooring material of claim 2, wherein the release layerhas a thickness of 0.10 to 2.0 mm.
 18. (canceled)
 19. (canceled)
 20. Theflooring material of claim 1, wherein the PLA resin is an amorphous PLAresin.